The present disclosure relates to medical needles. More particularly, the present disclosure relates to phlebotomy needles with a flashback sensor.
Phlebotomy is the process of removing blood for a variety of medical and scientific purposes. This process entails the penetration of a human vein by a medical device containing a hollow needle to draw blood. Phlebotomy is an invasive procedure and, when conducted improperly, may lead to infection or physical trauma at the penetration site, or it may simply fail to yield a sufficient quantity of blood. Therefore, healthcare personnel, including medical students, nurses, and healthcare technicians, require training to properly use a medical device during a phlebotomy.
The state of the art contains numerous examples of medical devices adapted to draw blood from patients. These devices include standard needle-syringes, butterfly needle sets, and phlebotomy needles. Typically, a butterfly needle set includes a hollow needle having a sharpened distal end and a proximal end. The proximal end of the hollow needle is secured to a needle hub. In turn, a proximal portion of the needle hub is connected to flexible tubing. The needle hub defines a fluid conduit communicating with the tubing and includes a pair of flexible, radially extending wings that facilitate grasping of the butterfly needle set by medical personnel. Generally, the flexible tubing is formed of a transparent material that allows medical personnel to visualize blood flow, i.e., flashback, through the tubing immediately proximal to the needle hub. Visualization of flashback permits medical personnel to confirm that the needle has been properly inserted into a patient.
Generally, phlebotomy needles do not include structures for sensing or visualizing flashback. Although the lack of a structure for visualizing flashback in phlebotomy needles is not a major drawback for more experienced medical personnel, for those having little experience drawing blood with phlebotomy needles, the lack of any means to confirm that the needle has been properly positioned within a patient may increase the time required to draw blood and add to the discomfort of the patient.
In an attempt to overcome the above disadvantages, U.S. Pat. No. 5,450,856 to Norris discloses a phlebotomy needle attached to a blood collection tube. This phlebotomy needle includes an outboard needle, an inboard needle and a bulb therebetween. The bulb is clear and allows medical personnel to visualize blood within the bulb when the outboard needle has been properly positioned within the vein of a patient. The bulb also includes a button that can be depressed by medical personnel to vent air from within the needle. Air within the needle prevents blood from flowing through the needle and must be vented.
U.S. Patent Application 60/877,937 by Weilbacher et al. (“Weilbacher”), filed on Dec. 29, 2006, also discloses a phlebotomy needle including a structure that permits visualization of flashback. This phlebotomy needle includes a distal needle portion, a proximal needle portion and a central needle portion. The central needle portion defines an opening and a fluid channel in communication with the opening. The phlebotomy needle additionally includes a material positioned adjacent to the opening. This material allows passage of air through the opening to exit the fluid channel while preventing passage of blood. In addition, the material enables visualization of blood flow.
Although the Norris and Weilbacher phlebotomy needles facilitate visualization of flashback, a need exists for other apparatus and methods for sensing flashback during phlebotomy.